This invention relates generally to telephony over a computer network and, more particularly, to a method and system for proxying a call originating from a public network to a computer on a private network using a publicly known alias available from a directory service.
Telephony over computer networks has become more and more popular in recent years. In particular, multi-party conferencing systems such as NETMEETING by the MICROSOFT CORPORATION have given consumers and businesses the ability to conduct full audio and visual teleconferencing over traditional computer networks, thereby avoiding the high costs associated with renting time at a dedicated conference center.
One problem associated with network telephony is that most private networks are protected from the outside through the use of a proxy or firewall. Therefore, the internal IP addresses of the computers behind the proxy are hidden from potential callers outside the private network. This makes it impossible for outside callers to call a computer on a private network directly. Thus, it can be seen that there is a need for a novel method and system for proxying telephony messages.
In accordance with this need, a method and system for proxying telephony messages is provided. According to the method and system, a proxy computer of a private network can receive incoming telephony messages from one or more computers of a public network and proxy them to computers within the private network. Similarly, the proxy computer can also receive outgoing telephony messages from within the network and proxy them to computers outside of the network. To enable inbound calls, a proxy program on the proxy computer looks for the presence of an alias in the call signaling messages, references a data structure to determine which computer on the network is associated with the alias, and proxies the call signaling and control messages between the callee computer and the calling computer based on the association, thereby creating a logical connection between the calling computer and the callee computer.